Piezoelectric materials deform when an external voltage is applied to them. Such materials are often called “bimorph materials.” When the external voltage is applied, a piezoelectric effect takes place as a result of the crystal lattice structure of bimorph materials. Crystals generally have a charge balance where negative and positive charges precisely cancel each other out along the rigid planes of the crystal lattice. When this charge balance is disrupted by applying physical stress to a crystal, the energy is transferred by electric charge carriers, creating a current in the crystal. With the converse piezoelectric effect, application of an external electric field to the crystal disrupts the neutral charge state, resulting in mechanical stress and readjustment of the lattice structure. This mechanical stress and readjustment causes the bimorph material to physically move in one or more directions.
One electrical component that does not currently exploit the piezoelectric effect is the transistor. Transistors are the fundamental switching and amplification elements of modern electronic circuitry. Like other electrical components, transistors have capacity limits, including maximum current ratings, breakdown voltages and power-dissipation ratings. When these ratings are exceeded, the transistor will not function properly. This requires the transistors selected for a given circuit to be able to handle the voltage and current demands of the circuit's most demanding loads. For example, if a circuit includes a load drawing 15A of current, a transistor in the circuit must function properly at 15A. Higher voltage and current capacity transistors are generally more expensive than lower capacity counterparts. Also, when a transistor is not switched on, it is merely taking up space on a semiconductor chip.